Feel like a mosquito target? It's not your imagination

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It's true. Mosquitoes really do have preferences. Their descent at barbecues and how they zero in on one person's ankle but leave others, none of it is accidental. And at last it can be explained.

If you are a sporty type, have type O blood and are not as skinny as you used to be, then your suspicions can be confirmed. For you, mosquitoes will go that extra mile.

Ten years of research into mosquito habits and two years persuading volunteers to be swarmed, has been enough for a Tokyo-based expert to draw conclusions.

Dr Yoshikazu Shirai, who holds a PhD in medical entomology, based his findings on tests he did on 64 people who held their arm in a humid enclosure for 10 minutes. By repeating the experiment twice on different days, each person was eventually exposed to 105 mosquitoes.

At a climate-controlled, summery 23 degrees, mosquitoes reveal their weaknesses. Men are slightly more likely to be bitten than women but it is blood type (regrettably, type O is common) and body heat that really get them interested. Leaner types are more likely to be spared.

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Mosquitoes have individual "appetites" that vary daily, said Dr Shirai. Also, they lose their craving for blood if they drink sugar water first.

Feeling sorry for the 64 volunteers? Don't. To avoid the ethical dilemma of potentially exposing healthy people to mosquito-borne illnesses, Dr Shirai de-beaked his mozzies.

After cooling the insects to induce sleep, Dr Shirai used a very fine blade to cut off their business ends - the proboscis - before warming them up again. Unfazed by the amputation, the mosquitoes behaved exactly as if they were intact - flying around, settling on a victim and trying to spear a vulnerable spot.

To prove it, Dr Shirai used his own arms to test biteless mosquitoes against intact mozzies. There was no difference except that he ended up with one very itchy arm. So deft did he become at cooling, cutting and reviving the insects that he could do the whole thing in three seconds, he said.